Chief Actuary Jobs
Chief Actuary jobs are open across insurance, consulting, financial services, and healthcare, from senior manager to executive level, with specializations in life and health, property and casualty, and enterprise risk management. Find a role that fits below and apply directly.
Find Chief Actuary JobsOverview
Showing 5 of 9+ Chief Actuary jobs
Your Future is our Future
At Lumeris, we believe that our greatest achievements are made possible by the talent and commitment of our team members. That's why we are actively seeking talented and collaborative individuals who are passionate about making a difference in the healthcare industry. Join us today as we strive to create a system of care that every doctor wants for their own family and become part of a community that values its people and empowers you to make an impact.
We're excited to consider every qualified candidate authorized to work in the United States, although we are unable to sponsor visas for this role at this time.
Position:
VP, Medicare Advantage Chief ActuaryPosition Summary:
Provides oversight, strategic direction, process improvements, and best practices for the department. Responsible for all actuarial and underwriting/pricing functions in support of Essence Healthcare’s Medicare Advantage plan operations. Partnering closely with the leaders of Risk Adjustment, Pharmacy, Health Plan Product, and Stars Strategy, this role delivers forward-thinking strategies and provides business direction regarding actuarial rate setting, pricing, annual CMS Part C and Part D bid submissions, risk adjustment factor forecasting, premium development, valuation and statutory reserve setting (including IBNR), financial risk management, product development, and performance analytics to maintain long-term financial sustainability, market competitiveness, and high Star Ratings performance.Job Description:
Primary Responsibilities:
- Strategic Leadership & Talent Development: Develops, implements, and guides strategic direction for the Medicare Advantage actuarial function. Oversees, coaches, mentors, motivates, supports, and develops a cross-functional team, building specialized internal capabilities in Medicare Advantage pricing, Part D benefit economics, reserving, risk adjustment, healthcare economics, and advanced healthcare analytics. Oversees goal setting/review, regular guidance and 1-1 check-ins, career development/planning, upskilling, resource allocation, staffing, budget creation/management, succession planning, and other People & Culture programs/activities as needed. Fosters accountability, collaboration, and innovation to ensure organizational goals are met.
- Executive Business Intelligence & Plan Performance: Oversees and supports cross-functional alignment to ensure the best possible business intelligence and understanding of company financials in communications to executive team and the Essence Healthcare Board of Directors; delivers clear visibility into emerging Medical Loss Ratios (MLR), emerging claims trends, membership and revenue dynamics, member cohort profitability, risk score performance, and regulatory revenue shifts.
- MA Product Design & Pricing Architecture: Serves as the primary actuarial authority for Medicare Advantage product strategy and pricing. Partners with Health Plan Product, Clinical, Pharmacy, Network, Finance, and Market Growth leaders to evaluate Plan Benefit Packages (PBPs), supplemental benefits (e.g., dental, vision, hearing, OTC allowances), formulary and cost-sharing structures, service-area expansion, and specialized plan offerings. Balances member value, growth objective, competitive positioning, regulatory requirements, while achieving margin targets.
- Valuation, Reserving & Risk Management: Responsible for actuarial valuation for financial reporting functions. Oversees pricing and valuation for all Essence Healthcare plan offerings. Directs the estimation and review of unpaid claim liabilities (IBNR), premium deficiency reserves, and risk-sharing settlements in strict accordance with statutory accounting principles (SAP), NAIC guidelines, and CMS Minimum Medical Loss Ratio (85% MLR) standards. Enhances risk management, internal controls, and pricing policies/procedures.
- CMS Bid Strategy & Submission Execution: Leads the end-to-end development, actuarial modeling, review, documentation, certification, and HPMS (Health Plan Management System) submission of annual Medicare Advantage Part C and Part D bids, ensuring 100% on-time adherence to statutory CMS June deadlines and full compliance with CMS Bid Instructions, Call Letters, and Actuarial Standards of Practice (ASOPs). Establishes rigorous assumption governance, scenario testing, quality controls, executive review, and bid-to-actual monitoring. Ensures compliance across all activities.
- Regulatory Policy & Executive Strategy: Informs and participates in pricing strategy discussions with executive team. Interprets and models the financial impacts of CMS Advance Notices, Final Rate Announcements, county benchmark adjustments, and risk adjustment model changes (such as the transition from CMS-HCC V24 to V28). Partners with the VP of Risk Adjustment to align risk score progression forecasts with bid pricing assumptions. Develops and implements new pricing strategies and methods to adapt to market dynamics.
- Regulatory Financial Settlement & Guidance: Ensures all actuarial financial statement items are established in accordance with relevant actuarial, regulatory, and accounting guidance, including CMS Part D risk corridor reconciliations, low-income cost-sharing (LICS) subsidies, federal reinsurance settlements, and Risk Adjustment Data Validation (RADV) accruals.
- Governance, Quality Assurance & Audit Readiness: Oversees the creation of and adherence to all key processes, procedures, analyses, and techniques. Guides department adoption of best practices to minimize inaccuracies and ensure compliance with legal, regulatory, and business requirements, maintaining full audit readiness for CMS financial exams, RADV audits (in coordination with the Risk Adjustment team), and RAPS/EDPS encounter data reviews.
- Innovative Methodologies & Star Ratings Economics: Creates continuous improvement initiatives by monitoring industry trends and developing best-in-class tools and techniques that ensure application of innovative actuarial methodology and adoption of actuarial best practices. Collaborates with the VP of Quality and Stars Strategy to quantify and incorporate the financial implications of CMS Star Ratings (Quality Bonus Payments and rebate percentages) into long-term strategic plans and multi-year bid curves.
- Cross-Functional Partnerships & Value-Based Care Alignment: Forges strong, productive, collaborative, cross-departmental relationships and serves as liaison. Consults, influences, shares data review/results, and positively impacts the adoption of strategic, statistically-sound business opportunities.
- Actuarial Program Leadership: Provides strategic direction for the Company actuarial program, establishing consistent study time and other exam-related guidelines to foster credentialing (ASA/FSA/MAAA) across junior and mid-level actuarial staff.
- Performance Analytics & Executive Dashboards: Provides pricing analysis, reports, and dashboards to track the performance of various programs, maintaining detailed bid-to-actual variance analyses, inpatient/outpatient unit cost trends, and risk score trajectory tracking.
Qualifications
- Bachelor’s degree in Actuarial Science, Mathematics, Statistics, Economics, or related quantitative field.
- Fellow of the Society of Actuaries (FSA) and a Member of the American Academy of Actuaries (MAAA) in good standing, meeting the qualification standards to issue Statements of Actuarial Opinion and CMS Medicare Advantage Part C and Part D Actuarial Certifications.
- 15+ years of health actuarial experience with at least 7–10 years of direct, senior leadership experience in Medicare Advantage bid preparation, Part C/Part D pricing development, reserving, risk adjustment, and CMS health plan financial management.
- Significant executive leadership within a Medicare Advantage organization, health maintenance organization (HMO), or national managed care carrier (e.g., Humana, Devoted, UnitedHealth, or prominent regional MA plans), with direct exposure to executive leadership and governing boards.
- Expert understanding of CMS bid mechanics, HPMS filings, CMS-HCC and RxHCC risk adjustment models, Part D direct subsidy/formulary economics, Star Ratings financial mechanics, and statutory IBNR reserving.
- Excellent financial knowledge and deep understanding of the economics, actuarial, and accounting aspects of the health care industry, specifically value-based care delivery, capitation, two-sided risk sharing, and Medicare Advantage statutory balance sheet management.
- Proven ability to develop, support, coach, mentor, and empower a cross-functional team of credentialed actuaries, students, and healthcare economics data analysts.
- Highly skilled at developing pricing strategies and plans for new products and innovative services, including specialized MA plans (e.g., Chronic or Dual-Eligible SNPs) and consumer-centric supplemental benefit packages.
- Proven ability to work collaboratively across functional teams and different organizational levels to deliver results under strict, non-negotiable statutory timelines (e.g., annual June CMS bid deadline).
- Demonstrated ability to partner with sales and growth teams to evaluate Annual Enrollment Period (AEP) targets, geographic service area expansions, and competitive market positioning.
- Strong communication and negotiation skills, with demonstrated experience presenting complex actuarial models and financial trade-offs to Executive Leadership, Plan Leaders, and Board Committees.
- Ability to effectively organize and prioritize dynamic workflow during high-pressure bid cycles and regulatory filing windows.
- Ability to work with integrity, ethically and continuously uphold organizational values
- Excellent written and verbal communication skills with the ability to influence at all levels.
Working Conditions
- While performing the duties of this job, the employee works in normal office working conditions.
Disclaimer
- The job description describes the general nature and level of work being performed by people assigned to this job and is not intended to be an exhaustive list of all responsibilities, duties and skills required. The physical activities, demands and working conditions represent those an employee encounters while performing the essential functions of this job. Reasonable accommodations may be made to enable individuals with disabilities to perform the essential job duties and responsibilities.
#LI-REMOTE
Pay Transparency:
Factors that may be used to determine your actual pay rate include your specific skills, experience, qualifications, location, and comparison to other employees already in this role. In addition to the base salary, certain roles may qualify for a performance-based incentive and/or equity, with eligibility depending on the position. These rewards are based on a combination of company performance and individual achievements.
The hiring range for this position is:
$175,300.00-$249,100.00Benefits of working at Lumeris
Medical, Vision and Dental Plans
Tax-Advantage Savings Accounts (FSA & HSA)
Life Insurance and Disability Insurance
Paid Time Off (PTO, Sick Time, Paid Leave, Volunteer & Wellness Days)
Employee Assistance Program
401k with company match
Employee Resource Groups
Employee Discount Program
Learning and Development Opportunities
And much more...
Be part of a team that is changing healthcare!
Member Facing Position:
No- Not Member or Patient Facing PositionDrug Screen Requirement:
NoMVR Required:
No
Credit Check Required:
NoLocation:
Virtual – Microsoft TeamsTime Type:
Full timeLumeris and its partners are committed to protecting our high-risk members & prospects when conducting business in-person. All personnel who interact with at-risk members or prospects are required to have completed, at a minimum, the initial series of an approved COVID-19 vaccine. If this role has been identified as member-facing, proof of vaccination will be required as a condition of employment.
Disclaimer:
The job description describes the general nature and level of work being performed by people assigned to this job and is not intended to be an exhaustive list of all responsibilities, duties and skills required. The physical activities, demands and working conditions represent those an employee encounters while performing the essential functions of this job. Reasonable accommodations may be made to enable individual with disabilities to perform the essential job duties and responsibilities.
Lumeris is an EEO/AA employer M/F/V/D.
Your Future is our Future
At Lumeris, we believe that our greatest achievements are made possible by the talent and commitment of our team members. That's why we are actively seeking talented and collaborative individuals who are passionate about making a difference in the healthcare industry. Join us today as we strive to create a system of care that every doctor wants for their own family and become part of a community that values its people and empowers you to make an impact.
We're excited to consider every qualified candidate authorized to work in the United States, although we are unable to sponsor visas for this role at this time.
Position:
VP, Medicare Advantage Chief ActuaryPosition Summary:
Provides oversight, strategic direction, process improvements, and best practices for the department. Responsible for all actuarial and underwriting/pricing functions in support of Essence Healthcare’s Medicare Advantage plan operations. Partnering closely with the leaders of Risk Adjustment, Pharmacy, Health Plan Product, and Stars Strategy, this role delivers forward-thinking strategies and provides business direction regarding actuarial rate setting, pricing, annual CMS Part C and Part D bid submissions, risk adjustment factor forecasting, premium development, valuation and statutory reserve setting (including IBNR), financial risk management, product development, and performance analytics to maintain long-term financial sustainability, market competitiveness, and high Star Ratings performance.Job Description:
Primary Responsibilities:
- Strategic Leadership & Talent Development: Develops, implements, and guides strategic direction for the Medicare Advantage actuarial function. Oversees, coaches, mentors, motivates, supports, and develops a cross-functional team, building specialized internal capabilities in Medicare Advantage pricing, Part D benefit economics, reserving, risk adjustment, healthcare economics, and advanced healthcare analytics. Oversees goal setting/review, regular guidance and 1-1 check-ins, career development/planning, upskilling, resource allocation, staffing, budget creation/management, succession planning, and other People & Culture programs/activities as needed. Fosters accountability, collaboration, and innovation to ensure organizational goals are met.
- Executive Business Intelligence & Plan Performance: Oversees and supports cross-functional alignment to ensure the best possible business intelligence and understanding of company financials in communications to executive team and the Essence Healthcare Board of Directors; delivers clear visibility into emerging Medical Loss Ratios (MLR), emerging claims trends, membership and revenue dynamics, member cohort profitability, risk score performance, and regulatory revenue shifts.
- MA Product Design & Pricing Architecture: Serves as the primary actuarial authority for Medicare Advantage product strategy and pricing. Partners with Health Plan Product, Clinical, Pharmacy, Network, Finance, and Market Growth leaders to evaluate Plan Benefit Packages (PBPs), supplemental benefits (e.g., dental, vision, hearing, OTC allowances), formulary and cost-sharing structures, service-area expansion, and specialized plan offerings. Balances member value, growth objective, competitive positioning, regulatory requirements, while achieving margin targets.
- Valuation, Reserving & Risk Management: Responsible for actuarial valuation for financial reporting functions. Oversees pricing and valuation for all Essence Healthcare plan offerings. Directs the estimation and review of unpaid claim liabilities (IBNR), premium deficiency reserves, and risk-sharing settlements in strict accordance with statutory accounting principles (SAP), NAIC guidelines, and CMS Minimum Medical Loss Ratio (85% MLR) standards. Enhances risk management, internal controls, and pricing policies/procedures.
- CMS Bid Strategy & Submission Execution: Leads the end-to-end development, actuarial modeling, review, documentation, certification, and HPMS (Health Plan Management System) submission of annual Medicare Advantage Part C and Part D bids, ensuring 100% on-time adherence to statutory CMS June deadlines and full compliance with CMS Bid Instructions, Call Letters, and Actuarial Standards of Practice (ASOPs). Establishes rigorous assumption governance, scenario testing, quality controls, executive review, and bid-to-actual monitoring. Ensures compliance across all activities.
- Regulatory Policy & Executive Strategy: Informs and participates in pricing strategy discussions with executive team. Interprets and models the financial impacts of CMS Advance Notices, Final Rate Announcements, county benchmark adjustments, and risk adjustment model changes (such as the transition from CMS-HCC V24 to V28). Partners with the VP of Risk Adjustment to align risk score progression forecasts with bid pricing assumptions. Develops and implements new pricing strategies and methods to adapt to market dynamics.
- Regulatory Financial Settlement & Guidance: Ensures all actuarial financial statement items are established in accordance with relevant actuarial, regulatory, and accounting guidance, including CMS Part D risk corridor reconciliations, low-income cost-sharing (LICS) subsidies, federal reinsurance settlements, and Risk Adjustment Data Validation (RADV) accruals.
- Governance, Quality Assurance & Audit Readiness: Oversees the creation of and adherence to all key processes, procedures, analyses, and techniques. Guides department adoption of best practices to minimize inaccuracies and ensure compliance with legal, regulatory, and business requirements, maintaining full audit readiness for CMS financial exams, RADV audits (in coordination with the Risk Adjustment team), and RAPS/EDPS encounter data reviews.
- Innovative Methodologies & Star Ratings Economics: Creates continuous improvement initiatives by monitoring industry trends and developing best-in-class tools and techniques that ensure application of innovative actuarial methodology and adoption of actuarial best practices. Collaborates with the VP of Quality and Stars Strategy to quantify and incorporate the financial implications of CMS Star Ratings (Quality Bonus Payments and rebate percentages) into long-term strategic plans and multi-year bid curves.
- Cross-Functional Partnerships & Value-Based Care Alignment: Forges strong, productive, collaborative, cross-departmental relationships and serves as liaison. Consults, influences, shares data review/results, and positively impacts the adoption of strategic, statistically-sound business opportunities.
- Actuarial Program Leadership: Provides strategic direction for the Company actuarial program, establishing consistent study time and other exam-related guidelines to foster credentialing (ASA/FSA/MAAA) across junior and mid-level actuarial staff.
- Performance Analytics & Executive Dashboards: Provides pricing analysis, reports, and dashboards to track the performance of various programs, maintaining detailed bid-to-actual variance analyses, inpatient/outpatient unit cost trends, and risk score trajectory tracking.
Qualifications
- Bachelor’s degree in Actuarial Science, Mathematics, Statistics, Economics, or related quantitative field.
- Fellow of the Society of Actuaries (FSA) and a Member of the American Academy of Actuaries (MAAA) in good standing, meeting the qualification standards to issue Statements of Actuarial Opinion and CMS Medicare Advantage Part C and Part D Actuarial Certifications.
- 15+ years of health actuarial experience with at least 7–10 years of direct, senior leadership experience in Medicare Advantage bid preparation, Part C/Part D pricing development, reserving, risk adjustment, and CMS health plan financial management.
- Significant executive leadership within a Medicare Advantage organization, health maintenance organization (HMO), or national managed care carrier (e.g., Humana, Devoted, UnitedHealth, or prominent regional MA plans), with direct exposure to executive leadership and governing boards.
- Expert understanding of CMS bid mechanics, HPMS filings, CMS-HCC and RxHCC risk adjustment models, Part D direct subsidy/formulary economics, Star Ratings financial mechanics, and statutory IBNR reserving.
- Excellent financial knowledge and deep understanding of the economics, actuarial, and accounting aspects of the health care industry, specifically value-based care delivery, capitation, two-sided risk sharing, and Medicare Advantage statutory balance sheet management.
- Proven ability to develop, support, coach, mentor, and empower a cross-functional team of credentialed actuaries, students, and healthcare economics data analysts.
- Highly skilled at developing pricing strategies and plans for new products and innovative services, including specialized MA plans (e.g., Chronic or Dual-Eligible SNPs) and consumer-centric supplemental benefit packages.
- Proven ability to work collaboratively across functional teams and different organizational levels to deliver results under strict, non-negotiable statutory timelines (e.g., annual June CMS bid deadline).
- Demonstrated ability to partner with sales and growth teams to evaluate Annual Enrollment Period (AEP) targets, geographic service area expansions, and competitive market positioning.
- Strong communication and negotiation skills, with demonstrated experience presenting complex actuarial models and financial trade-offs to Executive Leadership, Plan Leaders, and Board Committees.
- Ability to effectively organize and prioritize dynamic workflow during high-pressure bid cycles and regulatory filing windows.
- Ability to work with integrity, ethically and continuously uphold organizational values
- Excellent written and verbal communication skills with the ability to influence at all levels.
Working Conditions
- While performing the duties of this job, the employee works in normal office working conditions.
Disclaimer
- The job description describes the general nature and level of work being performed by people assigned to this job and is not intended to be an exhaustive list of all responsibilities, duties and skills required. The physical activities, demands and working conditions represent those an employee encounters while performing the essential functions of this job. Reasonable accommodations may be made to enable individuals with disabilities to perform the essential job duties and responsibilities.
#LI-REMOTE
Pay Transparency:
Factors that may be used to determine your actual pay rate include your specific skills, experience, qualifications, location, and comparison to other employees already in this role. In addition to the base salary, certain roles may qualify for a performance-based incentive and/or equity, with eligibility depending on the position. These rewards are based on a combination of company performance and individual achievements.
The hiring range for this position is:
$175,300.00-$249,100.00Benefits of working at Lumeris
Medical, Vision and Dental Plans
Tax-Advantage Savings Accounts (FSA & HSA)
Life Insurance and Disability Insurance
Paid Time Off (PTO, Sick Time, Paid Leave, Volunteer & Wellness Days)
Employee Assistance Program
401k with company match
Employee Resource Groups
Employee Discount Program
Learning and Development Opportunities
And much more...
Be part of a team that is changing healthcare!
Member Facing Position:
No- Not Member or Patient Facing PositionDrug Screen Requirement:
NoMVR Required:
No
Credit Check Required:
NoLocation:
Virtual – Microsoft TeamsTime Type:
Full timeLumeris and its partners are committed to protecting our high-risk members & prospects when conducting business in-person. All personnel who interact with at-risk members or prospects are required to have completed, at a minimum, the initial series of an approved COVID-19 vaccine. If this role has been identified as member-facing, proof of vaccination will be required as a condition of employment.
Disclaimer:
The job description describes the general nature and level of work being performed by people assigned to this job and is not intended to be an exhaustive list of all responsibilities, duties and skills required. The physical activities, demands and working conditions represent those an employee encounters while performing the essential functions of this job. Reasonable accommodations may be made to enable individual with disabilities to perform the essential job duties and responsibilities.
Lumeris is an EEO/AA employer M/F/V/D.
See All 9 Chief Actuary Jobs
Find roles that match your experience and apply in just a few clicks.
Find Chief Actuary JobsChief Actuary Job Market
Who's Hiring
Top Industries Hiring
- Insurance
What Employers Look For
The qualifications that appear most often in chief actuary jobs.
- Fellowship designation such as FSA or FCAS from a recognized actuarial society
- Ten or more years of progressively senior actuarial experience in a relevant line of business
- Deep expertise in reserving, pricing, or capital modeling within insurance or financial services
- Demonstrated leadership of actuarial teams and cross-functional collaboration with finance and risk
- Proficiency in actuarial software such as MG-ALFA, GGY AXIS, or Prophet alongside R or Python
- Strong communication skills for presenting reserve opinions and risk findings to boards and regulators
Tips for Your Chief Actuary Job Search
Lead your resume with fellowship credentials
Put your FSA, FCAS, or MAAA designation in the top section of your resume, not buried in education. Many applicant tracking systems filter on fellowship status before a human ever reads your application, so front-loading credentials gets you past the first cut.
Quantify the reserves you have managed
Hiring committees want to see the scale of risk you have overseen. Replace vague claims with specific reserve volumes, model accuracy improvements, or capital savings your recommendations produced. Concrete figures distinguish your resume from candidates with identical credentials.
Apply early to roles that fit
Migrate Mate lists chief actuary openings from across the United States in one place, so you can find roles that match and apply directly to each listing.
Target postings by regulatory environment
Filter openings by the regulatory framework that matches your background, such as NAIC compliance, Solvency II, or IFRS 17. Demonstrating fluency in the exact regulatory context an employer operates in moves you ahead of generalists during the first screen.
Prepare a model governance case study
Interviewers at the C-suite level expect you to describe how you built or overhauled a reserving or pricing model, not just that you used one. Prepare a two-minute narrative covering the problem, your analytical approach, the governance controls you put in place, and the business outcome.
Negotiate total compensation, not just base
Chief actuary offers typically include long-term incentive plans, deferred compensation, and performance bonuses that can dwarf base salary. Before accepting, request the full compensation schedule in writing and confirm vesting timelines, so you can compare offers on equal footing.
Chief Actuary Jobs: Frequently Asked Questions
Which companies are hiring the most chief actuarys?
Protective, Aon, and Berkley are hiring the most chief actuarys right now, with openings concentrated in Massachusetts, Nebraska, and Georgia, based on current listings on Migrate Mate as of November 2026. Demand is especially active at large insurers and consulting firms managing regulatory and capital reporting cycles.
How many chief actuary jobs are remote?
About 50% of chief actuary openings are fully remote or hybrid as of November 2026, reflecting how board reporting and regulatory sign-off duties have adapted to distributed work. Roles focused on enterprise risk modeling and pricing tend to offer the most remote flexibility, while positions requiring frequent regulator or board interaction are more likely to expect regular in-office presence.
How do you become a chief actuary?
You become a chief actuary by completing a fellowship designation through the Society of Actuaries or Casualty Actuarial Society, then building experience across pricing, reserving, and capital management in increasingly senior roles. Moving into a director or VP of actuarial function positions you to demonstrate the leadership, regulatory communication, and business strategy skills that chief actuary searches require before you can credibly compete for the top seat.
Can you get a chief actuary job with limited experience?
A chief actuary role is almost universally a senior executive position, so employers expect a fellowship credential and extensive hands-on experience before considering any candidate. If you are earlier in your career, the most direct path is securing a lead or director-level actuarial role where you can own a full reserving or pricing process, build regulatory relationships, and develop the board-facing communication skills that distinguish chief actuary candidates from technically strong but leadership-light applicants.
What does the chief actuary interview process look like?
The process typically starts with a recruiter or HR screen to verify credentials and experience level, followed by a technical interview with the CFO, CRO, or current actuarial leadership testing your reserving philosophy and regulatory opinion experience. Later rounds usually involve a presentation to the executive team or board on a risk or capital topic, and final conversations often probe your approach to talent management and your track history overseeing model governance and audit responses.
Where can I find and apply to chief actuary jobs?
You can find and apply to chief actuary jobs on Migrate Mate, which lists current openings from across the United States. Find roles that match your credentials and experience, then apply directly to each listing that fits.
See All 9 Chief Actuary Jobs
Find roles that match your experience and apply in just a few clicks.
Find Chief Actuary Jobs