UnitedHealth Group (UNH), the nation’s largest health insurer, said its fourth-quarter profit rose 15% amid higher enrollments and strong results from its health services business.

The company reported on Thursday a profit of $1.43 billion compared to $1.24 billion in the year-ago period. On a per-share basis, earnings rose to $1.41 from $1.20 a share. Revenue climbed 8.2% to $31.12 billion.

Analysts were expecting per-share earnings of $1.40 and revenue of $31.07.

UnitedHealth continued to benefit from growth in its membership base, which increased to 88.2 million people in the latest period from 83.7 million last year. The company served 89.7 million people in the third quarter.

Revenue from UnitedHealth’s insurance business rose 7.3% to $28.81 billion. Optum, a health services business, logged a 35% increase in revenue to $10.2 billion.

UnitedHealth said its consolidated medical-care ratio, which gauges the amount of insurance premiums used for patient care, widened to 81.2% from 80.5%.

Operating costs rose 7.5% to $28.67 billion.

UnitedHealth’s fourth quarter ended Dec. 31, just before healthcare coverage through insurance exchanges kicked in. Leading up to the launch of those exchanges, health insurance providers generally saw stronger results, as many patients continued to avoid doctor’s offices amid a tepid economy.

Shares were down 2.4% at $73.01 in early morning trading.

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