Is the $ I withdrew from my IRA to redeposit with US govt to boost my federal employees retirement check considered a rollover to a retirement acct or a payout?

My fed retirement 1099 shows a gross distribution and a lower taxable amt, presumably to show a portion of the payout is a return of the $ I redeposited. (Years ago I cashed out of the retirement plan. I had the opportunity to redeposit $ to boost my monthly retirement check).